I also agree.
I know of many cases where a good shot on the range had poor perfomance in a lethal force encounter, and a poor shot on the range prevailed in a lethal force encounter. I can only assume that mindset was the determining factor.
I pushed for and got (although I didn't get the credit) force on force training for my old Dept.
While I love to compete in IDPA, and IPSC style matches and think they are good for training skills, they over emphasize speed at the expence of tactics. I played paintball and loved the speedball games, but guns that hold 200+ rounds with hundreds of rounds to reload with ruin the training factor.
Sim. guns have to be one of the greatest training aids for leathal force encounters, and do more to help in training in tactics, decission making and firearms skills, than JUST a flat range. It's certainly different when the targets shoot back.
Self defense isn't just a .38, but a layered system that goes from awareness all the way up to leathal force with many levels inbetween. If you don't include all of them in training, it will be difficult to shift from one level of force to another.